Featured Article

Underwater Docking Stations Developed for Robots to Recharge

Using robots for undersea exploration is nothing new, but as such technology is becoming more mainstream, it’s starting to pose a significant problem: the robots are running out their batteries too quickly.

Bluefin Robotics has come up with an innovative possible solution, however, involving docking stations for recharging the batteries at sea. Specifically, the charging stations would be located at the bottom of the ocean floor, which an autonomous underwater vehicle (AUV) could access to refuel after its battery life runs out.

A typical battery life for such vehicles is about 24 hours, so the charging stations would get a lot of traffic, and could make undersea explorations much more efficient.

“The limitation of these machines is power,” said Christopher Moore, an AUV manager at Phoenix International. “You need power to move a lot of data in an efficient amount of time, recharge the batteries, and accept a new mission.”

Bluefin is located on the Fore River in Quincy, where they have built the first docking station that can communicate directly with AUVs, guiding them to where they can recharge. The actual station is five feet by 15 feet, with a cone-shaped entrance, and uses inductive coils to recharge the AUVs wirelessly.

According to executives at Bluefin, AUVs using the docking station could work for months at a time, instead of the shorter missions they have been limited to thus far. This could mean big things for the Navy--in fact, Navy officials have already been taking an interest in Bluefin’s station.

With the ability to recharge, AUVs could someday be used to gather military intelligence about enemy submarine movements, and could even be used to neutralize or arm underwater mines. Even non-military AUVs, those used to gather data on undersea life, could use docking stations to upload the data they have gathered, giving researchers more flexibility than they’ve ever had before.

“Launch and recovery form a boat is a very difficult process,” he said. “This way you have a garage. So instead of doing launch and recovery every day, you can do it once a week or longer.”

Ben Allen, a senior engineer at Woods Hole Oceanographic Institution, elaborated, “When you attach a subsea cable and run power through it, it means you can power and point the vehicle for multiple missions. You have it recharge without bringing it back in, so you greatly minimize the expenses for ship operations.”

The Bluefin Robotics docking station had an eight-hour long demonstration around this time last year, which launched an AUV outside of Boston Harbor. The AUV was then positioned using GPS, guided to the docking station, docked there to recharge.

The technology works, and the implications are vast.

Duane Fotheringham, vice president of operations at Hydroid, commented on the excitement, saying, “The Interest in docking stations is to move the autonomy one step further and remove the men from the loop and take advantage of the robotics as much as possible. It’s an evolution of the technology as people become more and more comfortable with underwater robotics.”